cloth simulation problem
While I haven't looked in detail at your cloth configuration, I notice that your model is less than 1 cubic unit in size.  I have found (much to my chagrin) that trying to run cloth physics on anything that small has the unfortunate result that the cloth jiggles around and eventually gets sucked up into whatever model it is supposed to be colliding with.

Try scaling the model(s) up by 100x and apply. Then set the scene units to centimeters (If you want units to display realistically).